The interaction between the base flow created by seepage through the unsatu++rated zone in a region between two parallel rivers and the flow caused by the gaining of water from wells positioned at arbitrary points over the region is analysed. Normally both flows are non-steady but, for the sake of simplicity, the base flow is here assumed to be steady whereas the yield of water from the single well is assumed to be a free function of time defined by the actual consumption which assumption leads to a non-steady flow towards the wells. A special result of the analysis is that it becomes possible to define the catchment area of the single well.